Returns TRUE if the attribute is already loaded from the image otherwise FALSE if the attribute has not been loaded.
To minimize memory usage the image control will delay loading the value of large attributes until the Value property is accessed.
Attributes can only be loaded while the orginal image is still loaded in the control. If you wish to keep the attributes collection after closing or otherwise changing the image you should call the Load method for any attributes that werent loaded while the original image is still loaded.
Public Property IsLoaded As Boolean